This invention relates to processing of organic waste for subsequent use or disposal to minimize environmental impact. More specifically the method processes animal excreta, particularly farm and other animals, for subsequent use as for example as a fuel or as organic fertilizer, soil enhancer and soil amendment.
There are current systems for processing animal excreta or manure that use a hydrolyzed vacuum drying process that uses steam heat for indirect heating of the manure that results in rapid sterilization and drying. The technology can process animal manure into a minimum content pathogenic, odorless product in an approximately two hour cycle continuous operation process.
The current art processing system includes an animal manure input and initial processing structure. Any initial leached water and gas odor is removed at this stage. The manure is then processed through a vacuum fermentation and drying machine. Inside the machine the manure is sanitized, crushed and dried while being continuously conveyed through the machine by a disk type conveyor.
The conveyor shaft and disks are hollow to allow steam vapor to be passed therethrough for heating the conveyed manure by indirect heat conduction. The manure is passed through the conveyor chamber in a low vacuum environment to aid fermentation and the removal of gases and condensed liquids. The gases and liquid are transported to a deodorizing facility. Use of indirect heating minimizing burning of material and adhesion of material to the conveyor chamber walls.
Use of the vacuum fermentation and drying machine as the initial drying stage for the material, manure, has been found to provide only tolerable levels of sterilization for the final output product of the process. A means to further sterilize the material requires implementation to achieve the desired purity of the end product.
In a typical existing processing plant the material is conveyed from the vacuum fermentation and drying machine to a continuous drying, cooling and screening machine. As the material is conveyed through a rotary drum, gas and vapor are removed by a negative pressure differential in the drum. This provides additional drying of the material. The extracted gas and vapor is transported for further processing. As part of the gas/vapor removal the conveyed material is cooled. The material is then passed through a screen or filter to remove any waste or debris. The finished product is then deposited in a storage element or hopper.
Ancillary elements are used with such manure treatment facilities, for example, bio-tanks to remove odor from waste produced during the process and effluent treatment plants for processing liquid waste removed during the process. The art of these elements is well known and not directly relevant to the improvement of the instant invention. Also, water boilers, cooling towers, and power and control elements are part of any such manure processing facility.
As can be seen there is a need for better sterilization of animal manure processed for reuse to promote better environmentally friendly manure products.
One object of the present invention is improved sterilization of processed animal manure for reuse thereof. Another object is integration of apparatus for sterilization into existing continuous process manure product facilities.